Fig. 3. Flexural stiffness distribution in wings of Manduca sexta and Aeshna multicolor, and in finite element models of M. sexta wings. In each graph, spanwise flexural stiffness is shown above (longer lines) and chordwise flexural stiffness below; dorsal measurements are in black and ventral measurements in gray. Each line within these groups represents the flexural stiffness distribution estimated from wing displacement measurements performed on a different individual. (A) Flexural stiffness distribution of male Manduca sexta forewings (N=9 spanwise, N=10 chordwise), and of finite element models with homogeneous (blue) and exponentially declining (red) vein and membrane material stiffness. (B) Flexural stiffness distribution of female Manduca sexta forewings (N=4 spanwise, N=9 chordwise). (C) Flexural stiffness distribution of male Aeshna multicolor forewings (N=8). (D) Flexural stiffness distribution of male Aeshna multicolor hindwings (N=8).